1. Field of the Invention
The present invention relates to a vehicle surroundings monitoring apparatus employing together a monitoring technique on the base of images and a monitoring technique using radar data and a traveling control system incorporating the apparatus.
2. Discussion of Related Arts
In recent years, such vehicle surroundings monitoring apparatuses as detecting traveling circumstances in front of an own vehicle by means of processing images taken by a camera mounted on a vehicle and the like and detecting information about a preceding vehicle traveling ahead of the own vehicle from the traveling circumstances, have been proposed. Further, various traveling control systems in which a follow-up control to the preceding vehicle or an intervehicle distance control between the own vehicle and the preceding vehicle are performed using such vehicle surroundings monitoring apparatuses, have been put into practical use.
In these vehicle surroundings monitoring apparatuses sometimes the ability of recognizing the preceding vehicle and the like is exacerbated due to adverse conditions such as rain, snow, fog, backlight, knighting driving and the like. Japanese Patent Application Laid-open No. Toku-Kai-Hei 6-230115 discloses a technology in which the intervehicle distance between an own vehicle and a preceding vehicle is obtained in two ways, one is processing images taken by a stereoscopic camera and the other is directly detecting the distance by a millimeter wave radar. The reliability of the intervehicle distances obtained in the respective ways is investigated based on exterior circumstances and the like and either of the intervehicle distances is selected based on the reliability.
However, the technology disclosed in Toku-Kai-Hei 6-230115 has a disadvantage that since the respective reliabilities of stereoscopic camera and millimeter wave radar are judged simply on the basis of the external circumstances, a proper intervehicle distance is rejected and wrong data are adopted in some cases.
Further, in the prior art, since only one of the two ways is adopted and the other is discarded as invalid, distance data of the vehicle surroundings monitoring apparatus are not efficiently used.